An instrumentation and data acquisition system for measuring brine plumes in coastal waters

In 1980 the Department of Energy began discharging brine into the Gulf of Mexico in conjunction with the development of the Strategic Petroleum Reserve. An instrumentation system was developed for monitoring the brine plume resulting from the discharge, and it has proved to be very reliable over the past five years of nearly monthly measurements of the brine plume emanating from the Bryan Mound and West Hackberry Strategic Petroleum Reserve sites. The purpose of this paper is to describe instrumentation which has been developed to measure the brine plumes resulting from the discharge of brine from a submerged multiport diffuser in coastal waters less than 30 m deep. A conductivity, temperature, depth, and dissolved oxygen (CTD/DO) instrument is housed in a sled and towed on the seafloor. The instrument is interfaced to an automatic data acquisition system for recording the CTD/DO data and the ship´s location. The system is relatively inexpensive and sufficiently accurate for evaluating the plume boundary to within 1 part per thousand above the ambient salinity.